Support single-file leagues in MatchHistory

[shawnhdx0710]

Summary

Football-data.co.uk publishes some leagues in a single file. The file holds the full match history for all seasons. The Swiss Super League is an example. These files live at /new/{league}.csv. They use a different subset of column names than the per-season files.

MatchHistory currently reads only the per-season files at /mmz4281/{season}/{league}.csv. For a single-file league, this URL does not exist. The request returns a 404. This change fixes issue #589.

What changed

• The change adds a single_file flag to the league config.
• For a single-file league, read_games downloads /new/{league}.csv once. It does not loop over the seasons.
• It maps the single-file column names to the per-season column names. It fills the missing columns with NaN.
• It filters the rows to the requested seasons.

How to use

Add a custom league to league_dict.json with the single_file flag:

{
  "SUI-Super League": {
    "MatchHistory": "SWZ",
    "single_file": true,
    "season_start": "Jul",
    "season_end": "May"
  }
}

Tests

Added test_read_games_single_file. It uses a synthetic fixture file. It does not hit the network.

Documentation

Updated docs/datasources/MatchHistory.ipynb.

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Fixes #589

[shawnhdx0710]

@probberechts